Grey paint help

Hi, I'm redecorating my bedroom and have decided to go for a grey feature wall. The room is opened out to the eaves so it's a really big wall.I've decided to go with Dulux warm pewter but am really stuck with what colour to go with it. I'm wanting it to be a white colour but not a bright white.So does anyone out there with a better idea of decoration know what would look best with it Thanks